/*
 * Copyright (c) 2013, 2016, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */
package com.oracle.truffle.r.nodes.builtin.base;

import static com.oracle.truffle.r.runtime.builtins.RBehavior.PURE;
import static com.oracle.truffle.r.runtime.builtins.RBuiltinKind.PRIMITIVE;

import com.oracle.truffle.api.dsl.Specialization;
import com.oracle.truffle.r.nodes.builtin.RBuiltinNode;
import com.oracle.truffle.r.runtime.RRuntime;
import com.oracle.truffle.r.runtime.builtins.RBuiltin;
import com.oracle.truffle.r.runtime.context.RContext;
import com.oracle.truffle.r.runtime.data.RNull;
import com.oracle.truffle.r.runtime.data.RTypedValue;

@RBuiltin(name = "isS4", kind = PRIMITIVE, parameterNames = {"object"}, behavior = PURE)
public abstract class IsS4 extends RBuiltinNode {

    public abstract byte execute(Object value);

    @Specialization
    protected byte isS4(@SuppressWarnings("unused") RNull object) {
        return RRuntime.asLogical(RContext.getInstance().isNullS4Object());
    }

    @Specialization(guards = "!isNull(object)")
    protected byte isS4(RTypedValue object) {
        return RRuntime.asLogical(object.isS4());
    }

    @Specialization(guards = "!isTypedValue(object)")
    protected byte isS4(@SuppressWarnings("unused") Object object) {
        return RRuntime.LOGICAL_FALSE;
    }

    protected boolean isTypedValue(Object object) {
        return object instanceof RTypedValue;
    }

    protected boolean isNull(RTypedValue object) {
        return object == RNull.instance;
    }
}
